The present invention relates to a printhead assembly for an ink jet printer. In particular, the present invention relates to the supply of ink to a pagewidth ink jet printhead chip.
In a portable system utilized for the control of ink flow to an ink jet printhead, it is necessary to ensure that the printhead continues to function and receive an ink supply in the presence of movement of the printhead due to its portability. Examples of portable systems include the recently filed PCT Application Nos. PCT/AU98/00550 and PCT/AU98/00549 filed by the present applicant.
For example, when utilized in a camera system with an internal printer, it is desirable to provide for proper operation and ink flow during movement of the portable camera system. Further, it is desirable to provide for such a system as cheaply and efficiently as possible. This is particularly the case where the camera is moved during a printing operation.
According to a first aspect of the invention, there is provided a printhead assembly for an ink jet printer, the printhead assembly comprising
an elongate manifold that defines a plurality of ink passages and is dimensioned to span a print area;
at least one elongate printhead chip that is mounted on the manifold also to span the print area, the printhead chip having a plurality of ink inlets, each ink inlet being in fluid communication with a respective ink passage of the manifold;
an elongate baffle unit that is mounted on the manifold so that the manifold is interposed between the at least one printhead chip and the baffle unit;
an elongate housing that is mounted on the baffle unit, the baffle unit and the housing defining at least one ink storage chamber and at least one respective inlet in fluid communication with the at least one ink storage chamber; and
a data and power supply arrangement that is connected to the at least one printhead chip so that control signals can be transmitted to the at least one printhead chip.
The manifold may be in the form of a molded, unitary structure that defines at least three sets of ink supply passages, each set corresponding with a respective ink to be used by the printhead chips, the manifold further defining an elongate recess in which the printhead chips can be received, the ink supply passages opening into the recess.
The baffle unit and the housing may define at least three longitudinally extending ink storage chambers, the manifold being received in the baffle unit with each set of ink supply passages being in fluid communication with one respective ink storage chamber, the baffle unit defining a series of spaced baffle members in each storage chamber to inhibit excessive ink movement upon movement of the printhead assembly.
The baffle unit may have a pair of opposed end walls and a pair of spaced longitudinal walls so that, with the housing, one ink storage chamber is defined between the end walls and the longitudinal walls and two ink storage chambers are defined between the end walls and respective longitudinal walls and side walls of the housing, one of the end walls defining three inlets in fluid communication with respective ink storage chambers.
The housing may define a number of hydrophobically sealed breather holes to permit the passage of air through the holes while inhibiting the passage of liquid through the holes.
The data and power supply arrangement may include a pair of bus bars that are mounted on the housing and a tape-automated bonding strip that extends about the housing and interconnects the bus bars and the printhead chips.
The printhead assembly may include a cover member that engages the housing to enclose the bus bars and the tape-automated bonding strip.
The invention extends to a printer that includes a printhead assembly as described above.
In accordance with a second aspect of the present invention, there is provided an ink supply arrangement for supplying ink to the printing arrangement of a portable printer, said ink supply arrangement including:
an ink supply unit including at least one storage chamber for holding ink for supply to said printing arrangement, said ink supply unit including a series of spaced apart baffles configured so as to reduce the acceleration of the ink within the unit as may be induced by movement of the portable printer, whilst allowing for flows of ink to the printing arrangement in response to active demand therefrom.
Preferably, the ink printing arrangement is in the form of a printhead which is connected directly to an ink supply arrangement in the form of an ink supply unit having an ink distribution manifold that supplies ink via a plurality of outlets to corresponding ink supply passages formed on the printhead.
In the preferred form, the printhead is an elongate pagewidth printhead chip and the baffles in the ink supply are configured to reduce acceleration of the ink in a direction along the longitudinal extent of the printhead and corresponding ink supply unit. Preferably, the ink supply unit has a series of storage chambers for holding separate color inks.
Preferably, the ink storage chamber or chambers are constructed from two or more interconnecting molded components.